Add Qt connection handler for date/time widgets

echo/qt/autoconnect.py

@@ -6,7 +6,8 @@
                       connect_text,
                       connect_button,
                       connect_combo_selection,
-                      connect_list_selection)
+                      connect_list_selection,
+                      connect_datetime)
 
 __all__ = ['autoconnect_callbacks_to_qt']
 
@@ -20,6 +21,7 @@
 HANDLERS['button'] = connect_button
 HANDLERS['combosel'] = connect_combo_selection
 HANDLERS['listsel'] = connect_list_selection
+HANDLERS['datetime'] = connect_datetime
 
 
 def autoconnect_callbacks_to_qt(instance, widget, connect_kwargs={}):
@@ -64,6 +66,10 @@ def autoconnect_callbacks_to_qt(instance, widget, connect_kwargs={}):
     * ``combotext``: the callback property is linked to a QComboBox based on
       the label of the entries in the combo box.
 
+    * ``datetime``: the callback property is linked to a QDateTimeEdit.
+      Note that this connection will also work for the more specific QDateEdit
+      and QTimeEdit widgets, as they are subclasses of QDateTimeEdit.
+
     Applications can also define additional mappings between type and
     auto-linking. To do this, simply add a new entry to the ``HANDLERS`` object::
 

echo/qt/connect.py

@@ -1,10 +1,11 @@
 # The functions in this module are used to connect callback properties to Qt
 # widgets.
 
+from datetime import datetime
 import math
 
 from qtpy import QtGui, QtWidgets
-from qtpy.QtCore import Qt
+from qtpy.QtCore import Qt, QDateTime
 
 import numpy as np
 
@@ -13,7 +14,7 @@
 
 __all__ = ['connect_checkable_button', 'connect_text', 'connect_combo_data',
            'connect_combo_text', 'connect_float_text', 'connect_value',
-           'connect_combo_selection', 'connect_list_selection',
+           'connect_combo_selection', 'connect_list_selection', 'connect_datetime',
            'BaseConnection']
 
 
@@ -580,3 +581,51 @@
     def disconnect(self):
         remove_callback(self._instance, self._prop, self.update_widget)
         self._widget.itemSelectionChanged.disconnect(self.update_prop)
+
+
+class connect_datetime(BaseConnection):
+    """
+    Connect a CallbackProperty to a QDateTimeEdit.
+    Since QDateEdit and QTimeEdit are subclasses of QDateTimeEdit, this connection
+    will work for those more specific widgets as well.
+    """
+
+    def __init__(self, instance, prop, widget):
+        super(connect_datetime, self).__init__(instance, prop, widget)
+        self.connect()
+
+    def update_prop(self):
+        qdatetime = self._widget.dateTime().toUTC()
+        value = np.datetime64(qdatetime.toPython())
+        setattr(self._instance, self._prop, value)
+
+    def update_widget(self, value):
+        if value is None:
+            value = np.datetime64('now')
+        dt = value.item()
+
+        # datetime64::item can return a date
+        # If this happens, we use midnight as our time
+        # (datetime is a subclass of date so we need to check this way)
+        if not isinstance(dt, datetime):
+            date = dt
+            time = datetime.min.time()
+        else:
+            date = dt.date()
+            time = dt.time()
+
+        qdatetime = QDateTime(date, time, Qt.TimeSpec.UTC).toTimeSpec(self._widget.timeSpec())
+        self._widget.setDateTime(qdatetime)
+
+    def connect(self):
+        add_callback(self._instance, self._prop, self.update_widget)
+        self._widget.dateTimeChanged.connect(self.update_prop)
+        self._widget.dateChanged.connect(self.update_prop)
+        self._widget.timeChanged.connect(self.update_prop)
+        self.update_widget(getattr(self._instance, self._prop))
+
+    def disconnect(self):
+        remove_callback(self._instance, self._prop, self.update_widget)
+        self._widget.dateTimeChanged.disconnect(self.update_prop)
+        self._widget.dateChanged.disconnect(self.update_prop)
+        self._widget.timeChanged.disconnect(self.update_prop)

echo/qt/tests/test_autoconnect.py

@@ -1,4 +1,8 @@
+from datetime import datetime
+
+from numpy import datetime64
 from qtpy import QtWidgets, QtGui
+from qtpy.QtCore import QDateTime, Qt
 
 from echo.qt.autoconnect import autoconnect_callbacks_to_qt
 from echo import CallbackProperty
@@ -47,13 +51,18 @@ def __init__(self, parent=None):
             self.bool_log.setCheckable(True)
             self.layout.addWidget(self.bool_log)
 
+            self.datetime_dob = QtWidgets.QDateTimeEdit(objectName="datetime_dob")
+            self.datetime_dob.setTimeSpec(Qt.TimeSpec.UTC)
+            self.layout.addWidget(self.datetime_dob)
+
     class Person(object):
         planet = CallbackProperty()
         dataset = CallbackProperty()
         name = CallbackProperty()
         age = CallbackProperty()
         height = CallbackProperty()
         log = CallbackProperty()
+        dob = CallbackProperty()
 
     widget = CustomWidget()
 
@@ -86,6 +95,11 @@ class Person(object):
     widget.bool_log.setChecked(True)
     assert person.log
 
+    dob = datetime(2000, 1, 1, 11, 52, 6)
+    qdob = QDateTime(dob.date(), dob.time(), Qt.TimeSpec.UTC)
+    widget.datetime_dob.setDateTime(qdob)
+    assert person.dob.item() == dob
+
     # Check that modifying the callback properties updates the Qt widget
 
     person.planet = 'mars'
@@ -106,6 +120,11 @@ class Person(object):
     person.log = False
     assert not widget.bool_log.isChecked()
 
+    dob = datetime(2010, 2, 3, 16, 22, 11)
+    person.dob = datetime64(dob)
+    qdatetime = widget.datetime_dob.dateTime().toUTC()
+    assert qdatetime.toPython() == person.dob.item()
+
 
 def test_autoconnect_with_empty_qt_item():
 

echo/qt/tests/test_connect.py

@@ -1,10 +1,14 @@
+from datetime import datetime
+
 import pytest
+from numpy import datetime64
 from unittest.mock import MagicMock
 
 from qtpy import QtWidgets
+from qtpy.QtCore import QDateTime, Qt
 
 from echo import CallbackProperty
-from echo.qt.connect import (connect_checkable_button, connect_text,
+from echo.qt.connect import (connect_checkable_button, connect_datetime, connect_text,
                              connect_combo_data, connect_combo_text,
                              connect_float_text, connect_value, connect_button,
                              UserDataWrapper)
@@ -211,3 +215,26 @@ class Example(object):
     assert e.a.call_count == 0
     button.clicked.emit()
     assert e.a.call_count == 1
+
+
+def test_connect_datetime():
+
+    class Example(object):
+        t = CallbackProperty()
+
+    e = Example()
+
+    widget = QtWidgets.QDateTimeEdit()
+    widget.setTimeSpec(Qt.TimeSpec.UTC)
+
+    conn = connect_datetime(e, 't', widget)  # noqa
+
+    dt = datetime(2010, 5, 7, 13, 15, 3)
+    qdt = QDateTime(dt.date(), dt.time(), Qt.TimeSpec.UTC)
+    widget.setDateTime(qdt)
+    widget.dateTimeChanged.emit(qdt)
+    assert dt == e.t.item()
+
+    dt = datetime(2020, 3, 4, 7, 48, 16)
+    e.t = datetime64(dt)
+    assert widget.dateTime().toUTC().toPython() == dt